For example, an industrial robot used in welding generally operates synchronously with a peripheral device such as a welding power source, a positioner, and a slider. As a method of the synchronization, for example, a method of controlling communication through a network using RS-232C, RS-485, RS-422, Ethernet (registered trademark), Controller Area Network (CAN) (registered trademark), or the like is used.
As a related art for establishing synchronization between devices, for example, Patent Document 1 discloses communication control device that communicates with one or a plurality of control devices through a network. The communication control device includes a non-periodic transmission unit that generates a transmission request at an arbitrary time, a periodic transmission unit that generates a transmission request in a fixed period, a communication unit that communicates transmission data of the non-periodic transmission unit and the periodic transmission unit with the network, and a schedule unit that transmits transmission contents of the periodic transmission unit to the communication unit, calculates a communication processing time required for non-periodic transmission unit communication processing in a transmission request, obtains a remaining time of the fixed period of the periodic transmission unit, compares the communication processing time with the remaining time of the fixed period, and transmits the transmission contents of the non-periodic transmission unit to the communication unit.